european college of sport science

Thursday, June 25th, 2009
08:30 - 10:00
Oral presentations
OP-PH07 Physiology 7
AGING AND RESISTANCE TRAINING INDUCED INCREASE IN MUSCLE SIZE
HULMI, J.J., SALMIJÄRVI, H., KATAJAVUORI, M., AHTIAINEN, J.P., HOLVIALA, J., SELÄNNE, H., KOVANEN, V., HÄKKINEN, K.,
MERO, A.A.
UNIVERSITY OF JYVÄSKYLÄ
Introduction: Resistance training (RT) increases muscle size but aging may (5) or may not (1) decrease this response. The present study
investigated muscle hypertrophy and gene expression adaptations to heavy RT in young and old healthy men.
Methods
Twenty-one previously untrained young men (26.0+-4.3 yrs) and 18 older men (61.2+-4.1) participated in a 21-week RT period, comprising
whole-body exercises twice a week. The training loads increased from 60 to 85% of 1RM, and the number of repetitions in each set
decreased from 15-20 to 5-6 during RT. Nineteen men (42.5+-20.0) served as controls (no RT). Vastus lateralis (VL) muscle fiber crosssectional
area (CSA), expression of muscle hypertrophy regulating genes (by Real-Time RT-PCR), and muscle force were analysed before
and after the 21-week period. Muscle biopsies were obtained 4-6 days after the last RT workout. Macronutrient intake was not controlled
but it was registered by 4-day diaries at weeks 0, 10.5 and 21.
Results: RT led to 1.2-1.4 -fold increases in strength of leg extensors and muscle fiber CSA (P